According to the American Association for the Study of Liver Disease (AASLD) Guidelines, imaging is recommended as the basis for liver cancer screening in patients at risk; however, the presence of elevated alpha-fetoprotein levels appears to be an important prognostic marker. Patients with markedly elevated AFP levels typically have poorer outcomes than those with low or normal levels. The definition of high is somewhat variable, but many studies have found that patients with levels above 400 nanograms/mL tend to have a poor prognosis. At this point, however, AFP levels do not factor into treatment decisions.